US20100134464A1 - Liquid crystal display - Google Patents
Liquid crystal display Download PDFInfo
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- US20100134464A1 US20100134464A1 US12/542,194 US54219409A US2010134464A1 US 20100134464 A1 US20100134464 A1 US 20100134464A1 US 54219409 A US54219409 A US 54219409A US 2010134464 A1 US2010134464 A1 US 2010134464A1
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- power supply
- voltage induction
- supply line
- liquid crystal
- balance
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133604—Direct backlight with lamps
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133603—Direct backlight with LEDs
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133612—Electrical details
Definitions
- the present disclosure relates to a liquid crystal display (LCD) device and, more particularly, to an LCD device capable of driving a light emitting diode (LED) provided to turn on a fluorescent lamp provided as a light source in darkness by using an induced voltage without employing a driving circuit to thus minimize a fabrication cost and power consumption.
- LCD liquid crystal display
- LED light emitting diode
- LCD liquid crystal display
- the LCD displays a desired image on its screen by controlling the amount of transmission of light according to a video signal applied to a plurality of control switching elements arranged in a matrix form.
- the LCD includes a liquid crystal panel including a color filter substrate, an upper substrate, and a thin film transistor (TFT) substrate, a lower substrate, which face, between which and a liquid crystal layer is formed, and a driver that supplies a scan signal and image information to the liquid crystal panel to operate the liquid crystal panel.
- TFT thin film transistor
- the LCD is not a self-emissive display device which does not emit light by itself, so it requires a light source for providing light to the liquid crystal panel.
- the LCD includes a backlight assembly including a light source to supply light to the liquid crystal panel, and a light guide plate and an optical sheet to convert light emitted from the light source into white uniform plane light.
- a light source for generating light in the backlight assembly includes a CCFL (Cold Cathode Fluorescent lamp), an EEFL (External Electrode Fluorescent Lamp), the LED, or the like.
- CCFL Cold Cathode Fluorescent lamp
- EEFL External Electrode Fluorescent Lamp
- the general LCD includes a liquid crystal panel 1 , a plurality of fluorescent lamps 2 disposed under the liquid crystal panel and supplying light to the liquid crystal panel 1 , an optical sheet 11 for converting light emitted from the fluorescent lamps 2 and supplying the converted light to the liquid crystal panel 1 , a lower cover 9 for receiving the plurality of fluorescent lamps, and a timing controller 10 disposed on a rear surface of the lower cover 9 and driving the liquid crystal panel 1 .
- a light emitting diode (LED) 8 for improving dark lighting is mounted on the timing controller 10 , and an LED driving unit (not shown) for driving the LED 8 is also mounted thereon.
- a hole 10 a is formed at a position of the lower cover 9 corresponding to the LED 8 to allow light emitted from the LED 8 .
- the general LCD having such configuration is advantageous in that the fluorescent lamps 2 are turned on in darkness by using light emitted from the LED 8 , but disadvantageous in that power is consumed to drive the LED driving unit to increase power consumption.
- the LED driving unit includes a plurality of circuit elements, increasing the size of the timing controller 10 on which the LED driving unit is mounted and increasing the fabrication cost.
- the fluorescent lamps 2 when the fluorescent lamps 2 are turned on in darkness, if a sequence related to a point of time at which a power voltage is applied to the fluorescent lamps 2 and a sequence related to a point of time at which the LED 8 is driven are not matched, the fluorescent lamps 2 would not be turned on.
- a liquid crystal display (LCD) device including: a liquid crystal panel; a plurality of fluorescent lamps disposed under the liquid crystal panel, supplying light to the liquid crystal panel, and having electrodes provided at both ends thereof; a balance printed circuit board (PCB) disposed at both ends of the plurality of fluorescent lamps and including a clip fastened to be electrically connected with the electrodes of the fluorescent lamps; a power supply line printed on the balance PCB so as to be electrically connected to the clip and supplying power to the electrodes of the fluorescent lamps; a first voltage induction line printed with a first area on the balance PCB at a first interval from the power supply line; a second voltage induction line printed with a second area on the balance PCB at a second interval from the power supply line; and a light emitting diode (LED) mounted on the balance PCB and having an anode connected to the first voltage induction line and a cathode connected to the second voltage induction line, wherein the first area is larger than the second area, the first interval is smaller
- FIG. 1 is a sectional view of a general liquid crystal display (LCD) device
- FIG. 2 is an exploded perspective view showing an LCD device according to an embodiment of the present disclosure
- FIG. 3 is a horizontal sectional view taken along line I-I′ of FIG. 2 ;
- FIG. 4 is a vertical sectional view taken along line II-II′ of FIG. 2 ;
- FIG. 5 is a vertical sectional view taken along line III-III′ of FIG. 2 ;
- FIG. 6 is an equivalent circuit diagram of a power voltage, a first capacitor, a second capacitor, and a light emitting diode of FIG. 3 .
- LCD liquid crystal display
- the LCD device includes: a liquid crystal panel 101 ; a plurality of fluorescent lamps 102 disposed under the liquid crystal panel 101 , supplying light to the liquid crystal panel 101 , and having electrodes 102 a provided at both ends thereof; a balance printed circuit board (PCB) disposed at both ends of the plurality of fluorescent lamps 102 and including a clip 104 fastened to be electrically connected with the electrodes 102 a of the fluorescent lamps 102 ; a power supply line 105 printed on the balance PCB 103 so as to be electrically connected to the clip 104 and supplying power to the electrodes 102 a of the fluorescent lamps 102 ; a first voltage induction line 106 printed with a first area on the balance PCB 103 at a first interval (d 1 in FIG.
- PCB balance printed circuit board
- a second voltage induction line 107 printed with a second area on the balance PCB 103 at a second interval (d 2 in FIG. 5 ) from the power supply line 105 ; and a light emitting diode (LED) 108 mounted on the balance PCB 103 and having an anode connected to the first voltage induction line 106 and a cathode connected to the second voltage induction line 107 .
- LED light emitting diode
- the first area is larger than the second area
- the first interval d 1 is smaller than the second interval d 2
- the power supply line 105 and the first voltage induction line 106 form a first capacitor C 1
- the power supply line 105 and the second voltage induction line 107 form a second capacitor C 2 .
- the liquid crystal panel 101 includes a color filter substrate 101 a , an upper substrate, and a thin film transistor (TFT) array substrate 101 b , a lower substrate. Although not shown, a liquid crystal layer is formed between the two substrates 101 a and 101 b.
- TFT thin film transistor
- a plurality of fluorescent lamps 102 are provided below the liquid crystal panel 101 to provide light to the liquid crystal panel 101 .
- the fluorescent lamp 102 includes a glass tube and electrodes 102 a made of metal and provided at both ends outside the glass tube.
- the glass tube has a tubular shape with both ends sealed, in which a discharge gas such as neon (Ne), argon (Ar), mercury (Hg), and the like. Phosphor is coated on the inner wall of the fluorescent lamp 102 .
- external electrode fluorescent lamps EFLs
- CCFLs cold cathode fluorescent lamps
- the plurality of fluorescent lamps 102 are disposed within a lower cover 109 , and the balance PCBs 103 are disposed at both sides adjacent to the electrodes 102 a of the fluorescent lamps 102 at an inner side of the lower cover 109 .
- the balance PCBs 103 are disposed in a second direction perpendicular to the first direction.
- a base of the balance PCBs 103 are made of an insulation material, and the power supply line 105 for supplying a power voltage to the electrodes 102 a of the fluorescent lamps 102 is printed in the section direction on the balance PCBs 103 .
- a first voltage induction line 106 having a first area and spaced apart at a first interval (d 1 in FIG. 4 ) from the power supply line 105 is printed in a second direction.
- a second voltage induction line 107 having a second area and spaced apart at a second interval (d 2 in FIG. 5 ) from the power supply line 105 is printed in the second direction.
- the first area of the first voltage induction line 106 is larger than the second area of the second voltage induction line 107 , and the first interval d 1 between the power supply line 105 and the first voltage induction line 106 is smaller than the second interval d 2 between the power supply line 105 and the second voltage induction line 107 .
- the power supply line 105 and the first voltage induction line 106 form the first capacitor C 1 with the base of the balance PCD interposed therebetween, and the power supply line 105 and the second voltage induction line 107 form the second capacitor C 2 with the base of the balance PCB 103 interposed therebetween.
- the balance PCB 103 includes a clip 104 fastened to the electrode 102 a of the fluorescent lamp 102 .
- the clip 104 is electrically connected with the power supply line 105 .
- the clip 104 is made of an insulation material. Only a portion contacting with the electrode 102 a of the fluorescent lamp 102 may be made of metal, or the entirety of the clip 104 may be made of metal. In either case, the clip 104 is connected with the power supply line 105 through soldering.
- the LED 108 having an anode connected with the first voltage induction line 106 and a cathode connected with the second voltage induction line 107 is mounted on the balance PCB 103 .
- the anode and cathode of the LED 108 are connected to the first voltage induction line 106 and the second voltage induction line 107 through soldering.
- the LED 108 is driven by a difference between a voltage induced to the first capacitor C 1 and a voltage induced to the second capacitor C 2 when power voltage is applied to the power supply line 105 . This will now be described in detail with reference to FIGS. 3 to 6 .
- FIG. 3 is a horizontal sectional view taken along line I-I′ of FIG. 2 , showing the power supply line 105 , the first voltage induction line 106 and the second voltage induction line 107 at an inner side of the balance PCB 103 .
- the power supply line 105 and the first voltage induction line 106 form the first capacitor C 1 with the base of the balance PCB interposed therebetween
- the power supply line 105 and the second voltage induction line 107 form the second capacitor C 2 with the base of the balance PCB interposed therebetween.
- regions 106 a and 107 a to be soldered with the anode and cathode of the LED 108 are provided at the end portions of the first voltage induction line and second voltage induction line 107 in FIG. 3 .
- FIG. 4 is a vertical sectional view taken along line II-II′ of FIG. 2 , showing the power supply line 105 and the first voltage induction line 106 at the inner side of the balance PCB 103 .
- FIG. 5 is a vertical sectional view taken along line III-III′ of FIG. 2 , showing the power supply line 105 and the second voltage induction line 107 at the inner side of the balance PCB 103 .
- the width L 1 of the first voltage induction line 106 is larger than the width L 2 of the second voltage induction line 107
- the first area of the first voltage induction line 106 is larger than the second area of the second voltage induction line 107
- the interval d 1 between the power supply line 105 and the first voltage induction line 106 is larger than the interval d 2 between the power supply line 105 and the second voltage induction line 107 .
- the capacitance of the first capacitor C 1 formed by the power supply line 105 and the first voltage induction line 106 is larger than that of the second capacitor C 2 formed by the power supply line 105 and the second voltage induction line 107 .
- FIG. 6 is an equivalent circuit diagram of a power voltage V applied to the power supply line 105 , the first capacitor C 1 , the second capacitor C 2 , and the LED 108 .
- the capacitance of the first capacitor C 1 is larger than that of the second capacitor C 2
- the voltage at both ends of the first capacitor C 1 is smaller than the voltage at the both ends of the second capacitor C 2
- voltage applied to the anode of the LED 108 is larger than the voltage applied to the cathode of the LED 108 .
- the LED 108 is driven by the voltage difference.
- the LED 108 when the power voltage V is applied to the power supply line 105 to drive the fluorescent lamp 102 , the LED 108 is driven by the power voltage V 2 and, at the same time, the power voltage V is supplied also to the fluorescent lamp 102 .
- the LED 108 helps early turn on the fluorescent lamp 102 when the fluorescent lamp 102 is driven in darkness.
- the LED 108 provided to turn on the fluorescent lamp 102 in darkness is driven with the induced voltage by using the first and second voltage induction lines 106 and 107 , the fabrication cost and power consumption can be minimized. Also, when the fluorescent lamp 102 is turned in darkness, the LED 108 and the fluorescent lamp 102 simultaneously start to be driven, without the necessity of sequence controlling.
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- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Crystallography & Structural Chemistry (AREA)
- Chemical & Material Sciences (AREA)
- Mathematical Physics (AREA)
- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Theoretical Computer Science (AREA)
- Liquid Crystal (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
- Liquid Crystal Display Device Control (AREA)
Abstract
Description
- This application claims the benefit of Korean Patent Application No. 10-2008-0120098 filed on Nov. 28, 2008, the entire content which is hereby incorporated by reference.
- 1. Field of the Disclosure
- The present disclosure relates to a liquid crystal display (LCD) device and, more particularly, to an LCD device capable of driving a light emitting diode (LED) provided to turn on a fluorescent lamp provided as a light source in darkness by using an induced voltage without employing a driving circuit to thus minimize a fabrication cost and power consumption.
- 2. Description of the Related Art
- In general, the application coverage of a liquid crystal display (LCD) extends because of its characteristics that it is lighter, thinner, and driven at a low power consumption. Thus, the LCD is commonly used as a means for displaying images in mobile computers, mobile phones, office automation equipment, or the like.
- The LCD displays a desired image on its screen by controlling the amount of transmission of light according to a video signal applied to a plurality of control switching elements arranged in a matrix form.
- The LCD includes a liquid crystal panel including a color filter substrate, an upper substrate, and a thin film transistor (TFT) substrate, a lower substrate, which face, between which and a liquid crystal layer is formed, and a driver that supplies a scan signal and image information to the liquid crystal panel to operate the liquid crystal panel.
- The LCD is not a self-emissive display device which does not emit light by itself, so it requires a light source for providing light to the liquid crystal panel. Thus, the LCD includes a backlight assembly including a light source to supply light to the liquid crystal panel, and a light guide plate and an optical sheet to convert light emitted from the light source into white uniform plane light.
- A light source for generating light in the backlight assembly includes a CCFL (Cold Cathode Fluorescent lamp), an EEFL (External Electrode Fluorescent Lamp), the LED, or the like.
- The general LCD will now be described with reference to the accompanying drawings.
- As shown in
FIG. 1 , the general LCD includes aliquid crystal panel 1, a plurality offluorescent lamps 2 disposed under the liquid crystal panel and supplying light to theliquid crystal panel 1, an optical sheet 11 for converting light emitted from thefluorescent lamps 2 and supplying the converted light to theliquid crystal panel 1, alower cover 9 for receiving the plurality of fluorescent lamps, and atiming controller 10 disposed on a rear surface of thelower cover 9 and driving theliquid crystal panel 1. - A light emitting diode (LED) 8 for improving dark lighting is mounted on the
timing controller 10, and an LED driving unit (not shown) for driving theLED 8 is also mounted thereon. Ahole 10 a is formed at a position of thelower cover 9 corresponding to theLED 8 to allow light emitted from theLED 8. - The general LCD having such configuration is advantageous in that the
fluorescent lamps 2 are turned on in darkness by using light emitted from theLED 8, but disadvantageous in that power is consumed to drive the LED driving unit to increase power consumption. Also, the LED driving unit includes a plurality of circuit elements, increasing the size of thetiming controller 10 on which the LED driving unit is mounted and increasing the fabrication cost. In addition, when thefluorescent lamps 2 are turned on in darkness, if a sequence related to a point of time at which a power voltage is applied to thefluorescent lamps 2 and a sequence related to a point of time at which theLED 8 is driven are not matched, thefluorescent lamps 2 would not be turned on. - This specification provides a liquid crystal display (LCD) device including: a liquid crystal panel; a plurality of fluorescent lamps disposed under the liquid crystal panel, supplying light to the liquid crystal panel, and having electrodes provided at both ends thereof; a balance printed circuit board (PCB) disposed at both ends of the plurality of fluorescent lamps and including a clip fastened to be electrically connected with the electrodes of the fluorescent lamps; a power supply line printed on the balance PCB so as to be electrically connected to the clip and supplying power to the electrodes of the fluorescent lamps; a first voltage induction line printed with a first area on the balance PCB at a first interval from the power supply line; a second voltage induction line printed with a second area on the balance PCB at a second interval from the power supply line; and a light emitting diode (LED) mounted on the balance PCB and having an anode connected to the first voltage induction line and a cathode connected to the second voltage induction line, wherein the first area is larger than the second area, the first interval is smaller than the second interval, the power supply line and the first voltage induction line form a first capacitor, and the power supply line and the second voltage induction line form a second capacitor.
-
FIG. 1 is a sectional view of a general liquid crystal display (LCD) device; -
FIG. 2 is an exploded perspective view showing an LCD device according to an embodiment of the present disclosure; -
FIG. 3 is a horizontal sectional view taken along line I-I′ ofFIG. 2 ; -
FIG. 4 is a vertical sectional view taken along line II-II′ ofFIG. 2 ; -
FIG. 5 is a vertical sectional view taken along line III-III′ ofFIG. 2 ; and -
FIG. 6 is an equivalent circuit diagram of a power voltage, a first capacitor, a second capacitor, and a light emitting diode ofFIG. 3 . - A liquid crystal display (LCD) device according to embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
- As shown in
FIG. 2 , the LCD device according to an embodiment of the present invention includes: aliquid crystal panel 101; a plurality offluorescent lamps 102 disposed under theliquid crystal panel 101, supplying light to theliquid crystal panel 101, and havingelectrodes 102 a provided at both ends thereof; a balance printed circuit board (PCB) disposed at both ends of the plurality offluorescent lamps 102 and including aclip 104 fastened to be electrically connected with theelectrodes 102 a of thefluorescent lamps 102; apower supply line 105 printed on thebalance PCB 103 so as to be electrically connected to theclip 104 and supplying power to theelectrodes 102 a of thefluorescent lamps 102; a firstvoltage induction line 106 printed with a first area on thebalance PCB 103 at a first interval (d1 inFIG. 4 ) from thepower supply line 105; a secondvoltage induction line 107 printed with a second area on thebalance PCB 103 at a second interval (d2 inFIG. 5 ) from thepower supply line 105; and a light emitting diode (LED) 108 mounted on thebalance PCB 103 and having an anode connected to the firstvoltage induction line 106 and a cathode connected to the secondvoltage induction line 107. - Here, the first area is larger than the second area, the first interval d1 is smaller than the second interval d2, the
power supply line 105 and the firstvoltage induction line 106 form a first capacitor C1, and thepower supply line 105 and the secondvoltage induction line 107 form a second capacitor C2. - The elements of the LCD device with such configuration according to the embodiment of the present invention will now be described.
- With reference to
FIG. 2 , theliquid crystal panel 101 includes acolor filter substrate 101 a, an upper substrate, and a thin film transistor (TFT)array substrate 101 b, a lower substrate. Although not shown, a liquid crystal layer is formed between the twosubstrates - A plurality of
fluorescent lamps 102 are provided below theliquid crystal panel 101 to provide light to theliquid crystal panel 101. - The
fluorescent lamp 102 includes a glass tube andelectrodes 102 a made of metal and provided at both ends outside the glass tube. The glass tube has a tubular shape with both ends sealed, in which a discharge gas such as neon (Ne), argon (Ar), mercury (Hg), and the like. Phosphor is coated on the inner wall of thefluorescent lamp 102. - In the following description, external electrode fluorescent lamps (EEFLs) will be taken as an example of the
fluorescent lamps 102, but the present invention is not limited thereto and thefluorescent lamps 102 may be cold cathode fluorescent lamps (CCFLs) within the scope of the present invention. - With reference to
FIG. 2 , the plurality offluorescent lamps 102 are disposed within alower cover 109, and thebalance PCBs 103 are disposed at both sides adjacent to theelectrodes 102 a of thefluorescent lamps 102 at an inner side of thelower cover 109. - With reference to
FIG. 2 , if thefluorescent lamps 102 are disposed in a first direction at the inner side of thelower cover 109, thebalance PCBs 103 are disposed in a second direction perpendicular to the first direction. - A base of the
balance PCBs 103 are made of an insulation material, and thepower supply line 105 for supplying a power voltage to theelectrodes 102 a of thefluorescent lamps 102 is printed in the section direction on thebalance PCBs 103. A firstvoltage induction line 106 having a first area and spaced apart at a first interval (d1 inFIG. 4 ) from thepower supply line 105 is printed in a second direction. A secondvoltage induction line 107 having a second area and spaced apart at a second interval (d2 inFIG. 5 ) from thepower supply line 105 is printed in the second direction. At this time, the first area of the firstvoltage induction line 106 is larger than the second area of the secondvoltage induction line 107, and the first interval d1 between thepower supply line 105 and the firstvoltage induction line 106 is smaller than the second interval d2 between thepower supply line 105 and the secondvoltage induction line 107. - The
power supply line 105 and the firstvoltage induction line 106 form the first capacitor C1 with the base of the balance PCD interposed therebetween, and thepower supply line 105 and the secondvoltage induction line 107 form the second capacitor C2 with the base of the balance PCB 103 interposed therebetween. - With reference to
FIG. 3 , the balance PCB 103 includes aclip 104 fastened to theelectrode 102 a of thefluorescent lamp 102. Theclip 104 is electrically connected with thepower supply line 105. - The
clip 104 is made of an insulation material. Only a portion contacting with theelectrode 102 a of thefluorescent lamp 102 may be made of metal, or the entirety of theclip 104 may be made of metal. In either case, theclip 104 is connected with thepower supply line 105 through soldering. - With reference to
FIG. 2 , theLED 108 having an anode connected with the firstvoltage induction line 106 and a cathode connected with the secondvoltage induction line 107 is mounted on thebalance PCB 103. The anode and cathode of theLED 108 are connected to the firstvoltage induction line 106 and the secondvoltage induction line 107 through soldering. - The
LED 108 is driven by a difference between a voltage induced to the first capacitor C1 and a voltage induced to the second capacitor C2 when power voltage is applied to thepower supply line 105. This will now be described in detail with reference toFIGS. 3 to 6 . -
FIG. 3 is a horizontal sectional view taken along line I-I′ ofFIG. 2 , showing thepower supply line 105, the firstvoltage induction line 106 and the secondvoltage induction line 107 at an inner side of thebalance PCB 103. With reference toFIG. 3 , thepower supply line 105 and the firstvoltage induction line 106 form the first capacitor C1 with the base of the balance PCB interposed therebetween, and thepower supply line 105 and the secondvoltage induction line 107 form the second capacitor C2 with the base of the balance PCB interposed therebetween. For reference,regions LED 108 are provided at the end portions of the first voltage induction line and secondvoltage induction line 107 inFIG. 3 . -
FIG. 4 is a vertical sectional view taken along line II-II′ ofFIG. 2 , showing thepower supply line 105 and the firstvoltage induction line 106 at the inner side of thebalance PCB 103.FIG. 5 is a vertical sectional view taken along line III-III′ ofFIG. 2 , showing thepower supply line 105 and the secondvoltage induction line 107 at the inner side of thebalance PCB 103. With reference toFIGS. 4 and 5 , the width L1 of the firstvoltage induction line 106 is larger than the width L2 of the secondvoltage induction line 107, the first area of the firstvoltage induction line 106 is larger than the second area of the secondvoltage induction line 107, and the interval d1 between thepower supply line 105 and the firstvoltage induction line 106 is larger than the interval d2 between thepower supply line 105 and the secondvoltage induction line 107. Accordingly, the capacitance of the first capacitor C1 formed by thepower supply line 105 and the firstvoltage induction line 106 is larger than that of the second capacitor C2 formed by thepower supply line 105 and the secondvoltage induction line 107. -
FIG. 6 is an equivalent circuit diagram of a power voltage V applied to thepower supply line 105, the first capacitor C1, the second capacitor C2, and theLED 108. As shown inFIG. 6 , because the capacitance of the first capacitor C1 is larger than that of the second capacitor C2, the voltage at both ends of the first capacitor C1 is smaller than the voltage at the both ends of the second capacitor C2, and accordingly, voltage applied to the anode of theLED 108 is larger than the voltage applied to the cathode of theLED 108. Thus, theLED 108 is driven by the voltage difference. - As so far described, in the LCD device according to the embodiment of the present invention, when the power voltage V is applied to the
power supply line 105 to drive thefluorescent lamp 102, theLED 108 is driven by the power voltage V2 and, at the same time, the power voltage V is supplied also to thefluorescent lamp 102. Thus, light emitted from theLED 108 helps early turn on thefluorescent lamp 102 when thefluorescent lamp 102 is driven in darkness. - In addition, because the
LED 108 provided to turn on thefluorescent lamp 102 in darkness is driven with the induced voltage by using the first and secondvoltage induction lines fluorescent lamp 102 is turned in darkness, theLED 108 and thefluorescent lamp 102 simultaneously start to be driven, without the necessity of sequence controlling. - As the present invention may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.
Claims (5)
Applications Claiming Priority (2)
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KR1020080120098A KR101215288B1 (en) | 2008-11-28 | 2008-11-28 | Liquid crystal display device |
KR10-2008-0120098 | 2008-11-28 |
Publications (2)
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US20100134464A1 true US20100134464A1 (en) | 2010-06-03 |
US8284180B2 US8284180B2 (en) | 2012-10-09 |
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US12/542,194 Expired - Fee Related US8284180B2 (en) | 2008-11-28 | 2009-08-17 | Liquid crystal display device |
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US (1) | US8284180B2 (en) |
KR (1) | KR101215288B1 (en) |
CN (1) | CN101750769B (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080088550A1 (en) * | 2006-10-17 | 2008-04-17 | Samsung Electronics Co., Ltd. | Dc-dc converter, liquid crystal display device, aging test apparatus of liquid crystal display device, and method thereof |
US20080174731A1 (en) * | 2007-01-18 | 2008-07-24 | Byeong Soo Kang | Liquid crystal display panel having power supply lines and liquid crystal display |
US20110043112A1 (en) * | 2008-04-24 | 2011-02-24 | Indice Pty Ltd | Power control |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
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KR101016289B1 (en) * | 2004-06-30 | 2011-02-22 | 엘지디스플레이 주식회사 | Backlight unit |
KR20060054826A (en) * | 2004-11-16 | 2006-05-23 | 삼성전자주식회사 | Reflector sheet, back light assembly having the same and display device |
KR101201309B1 (en) * | 2005-06-30 | 2012-11-14 | 엘지디스플레이 주식회사 | Backlight unit |
WO2008068922A1 (en) * | 2006-12-08 | 2008-06-12 | Sharp Kabushiki Kaisha | Backlight device and display apparatus utilizing the same |
-
2008
- 2008-11-28 KR KR1020080120098A patent/KR101215288B1/en active IP Right Grant
-
2009
- 2009-08-17 US US12/542,194 patent/US8284180B2/en not_active Expired - Fee Related
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Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080088550A1 (en) * | 2006-10-17 | 2008-04-17 | Samsung Electronics Co., Ltd. | Dc-dc converter, liquid crystal display device, aging test apparatus of liquid crystal display device, and method thereof |
US20080174731A1 (en) * | 2007-01-18 | 2008-07-24 | Byeong Soo Kang | Liquid crystal display panel having power supply lines and liquid crystal display |
US20110043112A1 (en) * | 2008-04-24 | 2011-02-24 | Indice Pty Ltd | Power control |
Also Published As
Publication number | Publication date |
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US8284180B2 (en) | 2012-10-09 |
KR20100061194A (en) | 2010-06-07 |
KR101215288B1 (en) | 2012-12-26 |
CN101750769B (en) | 2012-02-01 |
CN101750769A (en) | 2010-06-23 |
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